As a conventional device for projecting an image to a wall surface or a screen, a so-called projector is used. A mainstream of the projector is a so-called stationary type device which is supplied with power from a commercial power supply and is used when it is fixed to a predetermined location. A projector as the stationary type projects, in its fixed state, an image to a given portion of the wall surface or to the screen.
Recently, on the other hand, a mobile projector compact in size and easy to carry is proposed as the projector. Also proposed as the mobile projector is a mobile phone with a projector function that includes a projector function and, a communication function. In such a mobile phone with the projector function, as a device for notifying an operator of an incoming call when the incoming call is received during using the projector function, there is a device described in Patent Literature 1. Patent Literature 1 also describes a method of notifying an incoming call with a ring tone.
Patent Literature 1 describes a mobile phone with a projector that is provided with a projection unit for projecting an optical image, a communication unit for performing communication with an external device, and a projection control unit for causing the projection unit to start projection indicating a notice such as an incoming call when the incoming call is received by the communication unit during the projection by the projection unit.
Patent Literature 2 and Patent Literature 3 describe methods of projecting an arrival notifying image for notifying the arrival of information to a user-visible projected plane using the projector when the information is received via a communication network, irrespective of whether the mobile phone is being used as the projector.